Textdump capture not generating "ddb.txt" when scripted via ddb utility

[Shrikanth Kamath]

I am trying to experiment with text dumps, and using the ddb utility
to script the necessary capture information when a panic is triggered.
The problem I am seeing is that ddb.txt is not getting generated as
the ddb capture is not set on when invoked via ddb utility.

I am doing the following

% /sbin/ddb script kdb.enter.panic="textdump set; capture on; show
pcpu; bt; ps; alltrace; capture off; reset"
% sysctl debug.ddb.textdump.pending=1
debug.ddb.textdump.pending: 0 -> 1

I drop to the debugger and trigger a panic, which promptly generates
the text dump but is creating only the following text files

%tar -xvf textdump.tar.1
x msgbuf.txt
x panic.txt
x version.txt

The ddb.txt is not generated. But if I drop to the debugger and do the
following after doing the above scripting,

db> capture on
db>show allpcpu
db>capture off

I am able to see the ddb.txt after triggering panic.

Question is why is /sbin/ddb script not effecting "capture on" when
done from command line? Am I missing any steps. Here are my settings

%sysctl -a | grep ddb

debug.ddb.capture.data:
debug.ddb.capture.bufsize: 49152
debug.ddb.capture.inprogress: 0
debug.ddb.capture.maxbufsize: 5242880
debug.ddb.capture.bufoff: 20523
debug.ddb.scripting.unscript:
debug.ddb.scripting.scripts: kdb.enter.panic=textdump set; capture on;
show pcpu; bt; ps; alltrace; capture off; reset

debug.ddb.textdump.do_version: 1
debug.ddb.textdump.do_panic: 1
debug.ddb.textdump.do_msgbuf: 1
debug.ddb.textdump.do_ddb: 1
debug.ddb.textdump.pending: 1
debug.ddb_use_printf: 0
debug.kdb.current: ddb
debug.kdb.available: ddb gdb ndb


This is in a FreeBSD 10 environment.

--
Shrikanth R K